Multispecific antibodies that specifically bind at least two different epitopes are provided. Structural variants of native antibodies (antibody analogs) are also provided. Also provided are multispecific antibodies and antibody analogs having a range of biological activities. Agonist and antagonist multispecific antibodies and agonist and antagonist antibody analogs are provided. Multispecific antibodies and antibody analogs conjugated with therapeutic and/or diagnostic agents are also provided, as are multispecific antibodies and antibody analogs conjugated with agents to increase in vivo half-life compared to multispecific antibodies and antibody analogs lacking such agents. In addition, methods of making multispecific antibodies and antibody analogs and compositions comprising multispecific antibodies and antibody analogs are provided. Therapeutic, research, and diagnostic uses of multispecific antibodies and antibody analogs are also provided.